For the first time, researchers have developed a way to view
stem cells in the brains of living animals, including humans—a finding that
allows scientists to follow the process neurogenesis (the birth of neurons). The
discovery comes just months after scientists confirmed that such cells are
generated in adult as well as developing brains.

This is important because we need to be able to measure the effects of
treatments targeted at repair in the brain. If you can't prove a drug is doing
repair, you don't know if it is working. It's also nice to know that our brains
do more repair on their own than previously thought.